1. Field of the Invention
The present invention relates to exercise apparatus and more particularly to an apparatus which utilizes hydraulic pressure for resistance and is adjustable over a wide range.
2. Description of the Prior Art
With the current interest in personal fitness, a variety of machines and apparatus have been proposed to permit a user to exercise various muscles in the body. The majority of these utilize weights or springs to provide resistance during exercising. Although some machines have been proposed which utilize hydraulic and pneumatic devices to provide resistance, there is no known machine which will allow the user to obtain desired exercise movement in any desired direction and with very wide and fine control over the resistance.
Typical of relevant prior art apparatus are the devices described in the following U.S. Pat. Nos.: 4,465,274 to Davenport; 4,357,010 to Telle; 4,257,593 to Keiser; 3,587,319 to Andrews; 4,363,481 to Erickson; and 4,354,676 to Ariel. Both Davenport and Telle disclose devices which permit movements in a vertical plane against an adjustable hydraulic loop. Keiser also shows an exercise which uses vertical movement with a compressed gas system providing resistance. A universally mounted pole is moved against three hydraulic damper devices in the Andrews patent. Vertical lifting devices working against hydraulic cylinders are taught by Erickson and by Ariel.
None of the known prior art appears to disclose apparatus, that can provide movement in almost any plane and simultaneous movement in more than one plane. Thus, there is a need for a device having multiple hydraulic cylinders which are independently adjustable and that can provide exercise for selected groups of muscles.